I have an inreach. I just upgraded from the ACR plb. I like the plb as it does not require a monthly subscription, but it is only an sos device so no tracking, mapping or messaging.
The inreach is fully functional without a phone, so of the phone dies,you get basic tracking, full messaging, and other basic gps functions. I dont think you can load maps into it so that is about all you loose.
Personally i work hard to not use gps. I prefer paper maps and situational awareness. Keeps me sharper., but i do pull out the gps when i get mixed up just to verify location.
The inreach has worked well. I was able to message people in remote parts of zimbabwe last month!